Mandulia provides a zooming visualization of the Mandelbrot Set as many Julia Sets, with Lua scripting support. Implemented in Haskell (main program), C (Julia Set renderer), and Lua (configuration and scripting). This is a 10-minute excerpt of Mandulia's "attract mode" in action, exploring points near the boundary of the Mandelbrot Set.
Source code provided, under GPLv3+ license, also installable from Hackage using cabal-install.
Note: an audio track is present in the video file, but it is silent throughout.